Energy dissipating inlet for clarifier feedwells

Abstract

An inlet structure for dissipating the energy of the influent to a feedwell of a clarifier. The inlet structure has a cylindrical wall centered in the clarifier and closed at the bottom. Ports in the wall are each equipped with a baffle that includes a fixed center vane aligned with the port, a pair of hinged gates on the sides of the center vane, and a bottom baffle underlying the port and the center vane and gates. The gates can be adjusted to control the size and velocity of influent streams that are directed in opposite tangential directions from each port into impingement with streams from adjacent ports for dissipation of the influent energy in the feedwell.

What is claimed is:  
     
       1. An inlet structure for directing influent liquid into a clarifier feedwell having an influent feed structure for receiving the influent liquid, said inlet structure comprising: 
       a generally cylindrical wall and a bottom cooperating to present a chamber in the feedwell for receiving the influent liquid from the influent feed structure, said wall having a plurality of ports for discharging the influent liquid from said chamber into the feedwell; and  
       a baffle structure on said wall for each port arranged to direct the influent liquid passing through each port in opposite directions generally tangentially to said wall.  
     
     
       2. An inlet structure as set forth in  claim 1 , wherein: 
       said baffle structure for each port is arranged to direct the influent liquid in opposite flowing streams; and  
       said ports are spaced closely enough apart that the streams from adjacent ports impinge on each other.  
     
     
       3. An inlet structure as set forth in  claim 1 , wherein each baffle structure includes a bottom baffle on said wall at a location below each port. 
     
     
       4. An inlet structure as set forth in  claim 3 , wherein said bottom baffles extend sidewardly beyond side edges of said ports. 
     
     
       5. An inlet structure as set forth in  claim 1 , wherein said baffle structure for each port comprises a pair of adjustable gates for deflecting the influent liquid in opposite directions, each gate being adjustable to direct the influent liquid more closely along or farther away from said wall. 
     
     
       6. An inlet structure as set forth in  claim 1 , wherein said baffle structure comprises: 
       a pair of adjustable gates for directing the influent in opposite directions; and  
       a substantially vertical axis on which each gate is mounted to pivot toward and away from said wall to thereby adjust how closely along said wall each gate directs the influent liquid.  
     
     
       7. An inlet structure as set forth in  claim 6 , wherein each baffle structure includes a fixed center vane spaced directly outwardly of each port, said gates being located on opposite sides of said center vane. 
     
     
       8. An inlet structure as set forth in  claim 7 , wherein each baffle structure includes a bottom baffle on said wall extending below each port and underlying both gates and said center vane. 
     
     
       9. An inlet structure as set forth in  claim 6 , wherein each gate can be releaseably secured at a plurality of different pivotal positions about said axis for the gate. 
     
     
       10. In a clarifier having an influent feed structure for receiving influent and a feedwell, the improvement comprising: 
       a generally cylindrical wall substantially centered in the clarifier and a bottom cooperating with said wall to provide a chamber in the feedwell for receiving the influent from the influent feed structure;  
       a plurality of ports in said wall for discharging the influent from said chamber into the feedwell; and  
       a baffle for each port located to direct the influent passing through the port in oppositely directed streams, said ports being arranged such that each stream impinges with a stream from an adjacent port to dissipate the energy of the streams entering the feedwell.  
     
     
       11. An improvement as set forth in  claim 10 , including a bottom baffle element on said wall at a location below each port and underlying said baffle. 
     
     
       12. An improvement as set forth in  claim 11 , wherein each baffle includes a pair of adjustable gates each mounted for pivotal movement about a substantially vertical axis for adjustment of how closely along said wall the streams are directed. 
     
     
       13. An improvement as set forth in  claim 10 , wherein each baffle includes a pair of adjustable gates each mounted for pivotal movement about a substantially vertical axis for adjustment of how closely along said wall the streams are directed. 
     
     
       14. An improvement as set forth in  claim 13 , wherein each baffle includes a fixed center vane spaced directly outwardly of each port, said gates being located on opposite sides of said center vane. 
     
     
       15. An improvement as set forth in  claim 13 , wherein each gate can be releaseably secured at a plurality of different pivotal positions about said axis for the gate. 
     
     
       16. A clarifier comprising: 
       a clarifier basin;  
       an influent feed structure for directing influent into said basin;  
       an open bottom feedwell generally centered in the clarifier;  
       an inlet structure having a generally cylindrical wall and a bottom cooperating to provide a chamber in the feedwell for receiving influent, said wall having a plurality of circumferentially spaced ports for directing influent into said feedwell; and  
       a baffle for each port located outwardly thereof and extending beyond opposite sides of each port to direct the influent tangentially from each port in opposite directions into impingement with influent from adjacent ports for dissipation of the influent energy.  
     
     
       17. A clarifier as set forth in  claim 16 , wherein each baffle includes a fixed bottom section located on said wall below each port. 
     
     
       18. A clarifier as set forth in  claim 16 , wherein each baffle includes a pair of pivotal gates each mounted to pivot in and out about a substantially vertical axis to adjust how closely along said wall the influent is directed by each gate. 
     
     
       19. A clarifier as set forth in  claim 18 , wherein each baffle includes a fixed center vane spaced directly outwardly of each port, said gates being located on opposite sides of said center vane. 
     
     
       20. A clarifier as set forth in  claim 19 , wherein each baffle includes a fixed bottom section located below each port and underlying said gates and center vane. 
     
     
       21. A method of dissipating energy of influent entering a feedwell in a clarifier, said method comprising: 
       providing a substantially cylindrical chamber in the feedwell; and  
       discharging influent from said chamber into the feedwell at a plurality of circumferentially spaced locations and in oppositely directed generally tangential directions with said locations being at substantially the same elevation and selected to effect direct and substantially head on impingement of the influent discharged from adjacent locations, thereby dissipating the energy of the influent entering the feedwell.  
     
     
       22. A method as set forth in  claim 21 , including the step of substantially closing said chamber at the bottom thereof.